Stability, bactericidal activity, vitamin B6 activity and gastrointestinal absorption of benzoic acid esters of pyridoxine.
alpha 4-O-Benzoyl-pyridoxine (PN-4'MB) and alpha 5-O-benzoyl-pyridoxine (PN-5'MB) were hydrolyzed in 10% aqueous solution of acetone at pH 1-4. They were hydrolyzed obeying apparent first-order kinetics. In the pH range of 1-7, PN-4'MB was hydrolyzed 10 times faster than PN-5'-MB. At pH 7-12, an interconversion between the two derivatives was observed. They were bactericidal against Escherichia coli and Bacillus subtilis and prevented severe convulsions induced in mouse by 4'-methoxypyridoxine, a potent antagonist of vitamin B6. PN-4'MB was hydrolyzed with the homogenate of rat liver more easily than PN-5'MB. The metabolite of PN-MBs in man was identified as 4'-pyridoxic acid, i.e., a principal metabolite of PN, using high-performance liquid chromatography. The amount of urinary excretion of 4'-pyridoxic acid in 10 hr after oral administration of PN-4'MB or PN-5'MB was as large as that of PN.
D000042:Absorption; D000818:Animals; D000900:Anti-Bacterial Agents; D001412:Bacillus subtilis / Q000187:drug effects; D001565:Benzoates / Q000494:pharmacology; D019817:Benzoic Acid; D004068:Digestive System Physiological Phenomena; D004355:Drug Stability; D004926:Escherichia coli / Q000187:drug effects; D006801:Humans; D008297:Male; D051379:Mice; D011735:Pyridoxic Acid / Q000652:urine; D011736:Pyridoxine / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000494:pharmacology; D051381:Rats; D012640:Seizures / Q000517:prevention & control
D000900:Anti-Bacterial Agents; D001565:Benzoates; C001737:4-methoxymethylpyridoxine; C031994:4-O-benzoyl pyridoxine; D011735:Pyridoxic Acid; C031995:5-O-benzoyl pyridoxine; D019817:Benzoic Acid; D011736:Pyridoxine